Protective means for parallel feeders.



PATENTED MAY 14, 1907.

L G. W. STONE.

PROTECTIVE MEANS FOR PARALLEL PEEDERS.

APPLIOATION FILED 00T.12, 1904.

Witnesses.

inventor. CharlesWStone.

transmission lines connected in tern may be reduced bv such an znnount that UNITED S'lfidiliiiit CHARLES ll. SlUNE, OF SQllEXE ELECTRIC COMPANY, A COR PROTECTSJE Specification of Letters t JL YORK.

i eras Patented. may 14, 1907.

Application filed October 12,190. Serial 110,228,162.

To mil whom it may concern.- Be it known that 1, CHARLES XV. S'roxn, a citizen of the United States, residing at Schenectady, county ol' Schenectady, State of New York, have invented certain new and usel'ul improvements in Protective Menus for Pit!- zt-llcl lleeders, of which the following is u specilicotion.

My invention relates to the protection oi transmission systems employing feeders or parallel tit both ends, and-its object is to provide etlicient and reliable means for nutonniticztllv cutting out one of the Lt'ceders or trttnsmission lines at both ends in case it becomes l short-circuited.

in tI'ttIlSllllSSlUIl systems employing" feeders connected in parallel at both ends, it is not sullicient to cut out uv feeder at the generating end when a short-circuit occurs o ereon, since current will be sup )lied from the other leeders buck t'roni the receiving end to the i'ault. in order to cut out the faulty leeder zit the receiving end, it has been progmsed l'ieretoi ore to employ relays comprising current and potential coils arranged to operate a switch to open the circuit oi the feeder upon tt reversal of eucrg'v Illow therein. Such devices are unreliable, however, on at heavy short-circuit, since the potential ot the svsthe potential coil oi the protective device is practically inoperative; so that the device is liable to fail at the time when its operation is most required.

By my invention the use of potentiol coils is entirely eliminated, current coils nl lie being utilized in the protective device.

y invention consists in placing switch between the feeders or sets of feeders at the receiving end with means for tripping: the switch upon a relative reversal oi ctr' ent flow in the feeders. Thus, if such it s' ch is inserted in the receiving bus-bars betv; en the connections of the two sets l' feeders t the l)tl$l)tlf5, a short-circuit on one. feedr will ztutonntticttllv open the bus-bar circui between the feeders, preventing 21-, flow-o current from the healthy feeder to the faulty l'eedcr. The inultvcl'eeder may then be disconnected from the bus-burs, and the untomntic switch cnn be again closed so as to supply all the bus-bars and the load corn;

l l l l l l l l l l l l l l l l l l f .to open swi ch S.

nected thereto from the feeder or feeders that are in operative condition. My invention will best be understood by rel'erenee to the ztct'rompzntving drawing, which shows dingrommntic: llv a transmission SIYSLLIII provided with protective means :11- rnng'ed in accordance with my inventin.

in the drawing A represents a source of nltermtting current at the generating station connected to the station bus-bars B. To these bus-burs ztre connected two or more l'eeders i and F through the switches S and These switches tire provided with the usuul overload tripping; devices, as indicated by the Pttlt'S or (oils :1 end c, catch pnir energized from :1. pair of series trzmsiormers t and The two feeders at the receiving station re connected to the bus-l nrs through the switches 5 end S, Which are not provided with overload tripping devices. The buslntrs at the receiving station are divided into two sections, 1th indicated by B and. B. These sections LLI'O connected by the switch b. which is provided with it trip coil "c and it butter 1) or energizing the circuit of the The circuit oi' the trip coil 0 ontrolled by two relays B it, which are 0 .noiniztllv open, and either oi which, when closed, closes the circuit oi the trip coil, so as lllttll relay is provided 'Wlill two c s which are connected to transis t and i in sinrilnr phases of the two 5 ers. 'ihese coils ere so connected that t the llov; eurre'nt'in the two feeders is in the stone reln ive direction, the magnetic one two coils will oppose each other ert no pull upon the I'Olztlt'. When a 9 short-circuit occurs. however, on one of the feeders, the current In one of the coils of one or both of the relz vs it will be reversed, relutive to the other coil, and consequently the combined. eli'ect of the two coils will draw up the rein closing the circuit of the tripcoil c throu lt battery 6, and opening This disconnects the faulty feeder from the bus-burs kit the receiving end, the circuit of the faulty feederheing opened at 9 the generttting end by the overload device. The i'nultv feeder may then be disconnected from the section of the receiving bus-bars, to which it is nornntll r connected,- and the switch 55 mnv then be closed. Thus, for in- 5 stnnce, the feeder i is short-circuited, the

si'iteh 55 may he opened after the switeh 5% has heen tripped, and the sn'i'teh bl may then 5 relays H. ll should he so proportioned that normal load on one feeder would not open the relay when the other feeder is open-eheuited, or else the relay should he short-eircoiled or the eireuit of die trip eoil 0 opened.

l do not desire to limit myself to the particular eonstruetion and arrangement of parts here shown. hut aim in the appended elaiins to eover all niodllit'atlrns Whieh are will u the s -ope of my invention l rat 1 claim hy Let ers Paient of the United States, is:

hus-hars ill the said feeders are connected, in ans for diseon- 11(!(;i.lll(tt(llS01()fftttltllfifl'OlH said l ns-hars, and ant'omat e means for opening the eireuit )e elosed, (onneetiirg hoth seetions B and ll 1 if the reeeiving' has-liars to the healthjv f1 ecler F, Whieh will then supply the entire load as indieatcd hy L L. The eoils of the as new and desire to seeure v in eomhina'tion with parallel feeders, hos-liars at the receiving station, switehes for oonneeting each set of feeders to said hushars, a switeh for opening the circuit of said bus-hairs hetween the first switches, a trip coil for the last switch, amt a difl'erentiahrehty j a switeh at the reeeiving end adapted to dis- 1 in eomhmation Willi parallel l'ee lers,'

receiving station ,to \\'hieh of said hus-hars between thepointsof eonneetion to said feeders upon a relalive reversal of enrrent in said feeders.

.21. upon a, relative reversal ha I operative of enrrent in said in comhination with parall l feeders.

3, hushars at the receiving station, switehes for oonneet'i eat-h set of feeders to said hashars; a sw to for opening the eireuit of said has-bars hetween the first switehes, a deviee having two normally-opposed magnet wind- 1 .illl feeders,

energized rospeetively from ';i d means controlled h: said deviee for openme; said swiloh.

ln eomhii ation with parallel feeders, hus-lnrs at the receiving station, sw tehes I eonneet said feeders. series transformers havin t heirprimaries in eireuit \rithsaid feeders a deriee having two n rn1ally-opp sed magnet windings energized from the seeondaries of said transformers, means eontrolled life ai ltle\'ieeforopeningsaids\\'iteh,and manu ally-eontrolled switehesadaptedtodiseonneet said feeders independentl of the Iirst svriteh.

T. ln eomhination with parallel feeders, litls-hars at the reeeiving station, switehes for eonneet ing' eaeh set of feeders to said huslHIIn" a switeh for opening the eireuit of said hus-hars hetween the lirst switehes, a trip coil for the last switeh, series transformers having their primaries in circuit with said feeders. and a, dilfermitial relay energized from the seeondaries of said transformers and eon-- trolling the eireuit of said trip eoil.

ln witness whereof l have hereunto set my hand this tenth day of tletoher, lfltl t.

tlhllllil ltl rl'. tl'lUXll.

itnesses:

l'lnnzxno ll nirrriisnlix,

llnrnx (human. 

